“A Song of Ice and Fire”—another verse from the world of ablation

The debate between the use of radiofrequency (RF) or cryoenergy for ablation near the atrioventricular (AV) conducting system or small coronaries has been fueled by the relative efficacies and risks of the two technologies, particularly in smaller hearts. The manuscript by Schneider et al adds another chapter to that ongoing debate.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/150576/1/jce13987.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/150576/2/jce13987_am.pd

Adenosine Mapping for Adenosine‐Dependent Accessory Pathway Ablation

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106956/1/pace12324.pd

Utility of Intrathoracic Impedance Monitoring in Pediatric and Congenital Heart Disease

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/99042/1/pace12134.pd

Patient and Procedural Correlates of Fluoroscopy Use During Catheter Ablation in the Pediatric and Congenital Electrophysiology Lab

ObjectiveTo identify factors associated with fluoroscopy use in pediatric and congenital heart disease (CHD) patients.DesignRetrospective cohort.SettingPediatric electrophysiology lab in a single tertiary‐care children's hospital.PatientsThree hundred eighty‐three patients who underwent electrophysiology study and ablation between January 2010 and December 2012.MethodsAblation procedures in which nonfluoroscopic navigation was employed were reviewed. Procedures using ≥10 minutes of fluoroscopy (high‐fluoroscopy time; HF) were compared with those using <10 minutes (low‐fluoroscopy time; LF). Group comparison of characteristics was made in the entire cohort and in CHD and anatomically normal heart subsets.ResultsDuring the study period, 416 ablation procedures were performed involving 471 substrates in 383 patients. Median fluoroscopy time was 6.7 minutes overall and 5.1 minutes with anatomically normal hearts. LF comprised 61% of all ablation and 69% of anatomically normal hearts. LF procedures were associated with anatomically normal hearts (93% vs. 63%; P < .0001). In anatomically normal hearts, HF was associated with accessory pathways (64% vs. 47%; P = .01), posteroseptal substrates (22% vs. 9%; P = .002), and ventricular substrates (12% vs. 1%; P < .0001). All cases of intra‐atrial reentrant tachycardia were HF. HF was associated with trans‐septal puncture (47% vs. 23%; P < .0001) though not when controlling for atrioventricular nodal reentrant tachycardia. LF was associated with cryoablation (56% vs. 17%; P < .0001).ConclusionsIn pediatric and congenital EP, ablation procedures using cryoablation and in patients with anatomically normal hearts are associated with LF. In accessory pathway ablation, HF was not associated with trans‐septal puncture.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111901/1/chd12213.pd

Frequency of CIED remote monitoring: A quality improvement follow‐up study

BackgroundBased on the findings of a prior study of CIED (Cardiac Implantable Electrical Device) remote monitoring (RM) frequency at the same center, the University of Michigan Congenital Heart Center (UMCHC) instituted a quality improvement (QI) change to reduce the frequency of routine CIED RM from every 2 months to every 3 months. The objective of this study is to determine the impact of this QI initiative to reduce workload without compromising patient care.MethodsThis is a single‐center, retrospective cohort study of all UMCHC patients with CIEDs followed via Medtronic CareLink CIED remote monitoring system from July 2015 to June 2017, after the QI change in 2014. The primary outcome was success of transition to new monitoring schedule. Secondary outcomes included complications, incidence of actionable events (AES), patient compliance, and change in workload. Outcomes were compared to the prior study.ResultsThere were 325 patients (mean age was 24  ±  14 years) included, of who 293 (90%) completely transitioned to the new RM schedule. During the study period, 96 transmissions included AES (4% of total), of which 50 (52%) were asymptomatic and discovered on routine monitoring. No patient experienced a complication attributable to decreased RM frequency. The mean number of interrogations decreased by 1.6 per patient over the 2‐year period compared to prior study.ConclusionsThis study demonstrated successful implementation of a QI initiative to reduce CIED monitoring frequency at a single center with no patient adverse events. The intervention reduced workload and potentially improved patient compliance with routine RM.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/150575/1/pace13707_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/150575/2/pace13707.pd

Antitachycardia Pacemakers in Congenital Heart Disease

BackgroundMany patients with congenital heart disease (CHD) acquire rhythm abnormalities related to their repair, most commonly intraatrial reentrant tachycardia (IART). Treatment of IART in CHD is often multifaceted, and may include medication, ablation, and pacing. Evidence regarding the use of antitachycardia pacing therapies is limited.ObjectiveThe aim of the study is to define the use and efficacy of antitachycardia pacing in patients with CHD at a single center.ResultsEighty implants were performed on 72 patients between 2000 and 2010. Follow‐up data of more than 3 months were available for 56 patients; median follow‐up time was 2.8 years. Twenty (36%) patients received successful antitachycardia pacing at a median 1.3 years postimplant. For those patients with IART after implant, antitachycardia pacing was successful in 57%. Patients with two‐ventricle repairs were more likely to have successful antitachycardia pacing than those with one‐ventricle palliation (45% vs. 17%, P = .04). Patients with documented IART had more successful antitachycardia pacing than those with no documented atrial tachycardia prior to implant (46% vs. 7%, P = .006). Early complications of antitachycardia pacemaker implant occurred in six patients (11%); late complications after implant occurred in three patients (5.6%). Of the initial 72 patients implanted, there were six deaths (8%).ConclusionsAntitachycardia pacing therapies were successful in the majority of CHD patients who had IART after implant. Patients without documented atrial tachycardia prior to implant were unlikely to require or receive successful therapy from antitachycardia pacemaker. Those patients postatrial switch procedure who had documented IART prior to implant had the highest incidence of successful antitachycardia pacing therapies. Antitachycardia pacemaker implantation is an adjunct to the management of IART in CHD patients, but may not benefit patients who have not yet demonstrated IART.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111221/1/chd12230.pd

Implantable Cardioverter Defibrillator Outcomes in Pediatric and Congenital Heart Disease: Time to System Revision

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/122425/1/pace12878.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/122425/2/pace12878_am.pd

Cosmetic outcomes and quality of life in children with cardiac implantable electronic devices

BackgroundAxillary implant location is an alternative implant location in patients for cardiac implantable electronic devices (CIEDs) for the purposes of improved cosmetic outcome. The impact from the patient’s perspective is unknown. The purpose of this study was to compare scar perception scores and quality of life (QOL) in pediatric patients with axillary CIED implant location versus the standard infraclavicular approach.MethodsThis is a multicenter prospective study conducted at eight pediatric centers and it includes patients aged from 8 to 18 years with a CIED. Patients with prior sternotomy were excluded. Scar perception and QOL outcomes were compared between the infraclavicular and axillary implant locations.ResultsA total of 141 patients (83 implantable cardioverter defibrillator [ICD]/58 pacemakers) were included, 55 with an axillary device and 86 with an infraclavicular device. Patients with an ICD in the axillary position had better perception of scar appearance and consciousness. Patients in the axillary group reported, on average, a total Pediatric QOL Inventory score that was 6 (1, 11) units higher than the infraclavicular group, after adjusting for sex and race (P = 0.02).ConclusionsQOL is significantly improved in axillary in comparison to the infraclavicular CIED position, regardless of device type. Scar perception is improved in patients with ICD in the axillary position.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147032/1/pace13522.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/147032/2/pace13522_am.pd

Decreased inappropriate shocks with new generation ICDs in children and patients with congenital heart disease

ObjectiveInappropriate implantable cardioverter defibrillator (ICD) shocks in children and patients with congenital heart disease (CHD) remain a major complication of device therapy, occurring in as many as 50% of children with ICDs. New generation devices include algorithms designed to minimize inappropriate shocks. This study aimed to evaluate the effect of new generation ICDs on the incidence of inappropriate shocks in the pediatric and CHD population.DesignRetrospective study of patients with CHD or under age 25 receiving ICDs between 2000 and 2015. New generation ICDs were defined as those with Medtronic “SmartShock” algorithms.ResultsTwo hundred eight devices were implanted in 146 patients. Rates of inappropriate shocks were similar between diagnoses (P = .71). The rate of inappropriate shock was 15% over median 5.8 years follow‐up. In the 36 patients (25%) with new generation ICDs, the rate of inappropriate shock was 6.3% over 4 years. Comparing old to new generation ICDs, freedom from first inappropriate shock was 90.6% versus 97.1% at 1 year and 80.4% versus 97.1% at 3 years (P = .01). Lead fracture was associated with having inappropriate shock (hazard ratio 8.5, P < .0001), and there was no significant difference between the device groups when lead fractures were excluded. Clinical actions were taken in 69% of patients after initial inappropriate shock (such as medication or program change, system revision, or explant). When an action was taken, subsequent inappropriate shock was reduced (5.3% vs 49.2% at 1 year; P = .002).ConclusionsPediatric and CHD patients are experiencing reduced inappropriate shocks with new generation ICD systems, though reduced lead fracture may account for this improvement. Clinical interventions after inappropriate shock favorably impact the subsequent rate of shocks once an inappropriate shock occurs.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/144309/1/chd12585_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/144309/2/chd12585.pd